1. Field of the Invention
The present invention relates to a time-measurement device having the capability of indicating time and also to a method of controlling such a time-measurement device.
2. Description of the Related Art
The present invention relates to a time-measurement device and a method of controlling the same. More specifically, the present invention relates to a time-measurement device having the capability of automatically switching the operating mode from a power saving mode to a normal mode and also to a method of controlling such a time-measurement device. A time-measurement device is known which includes an electric power generator, a power supply, and an electric power consuming part wherein electric power generated by the electric power generator is stored in the power supply and the electric power stored in the power supply is consumed by the electric power consuming part. Some time-measurement devices of this type have, in addition to a normal driving mode in which electric power is consumed, a power saving mode in which the electric power consumed by the electric power consuming part is saved, wherein the operating mode is switched to the power saving mode depending on the condition in which a user uses the time-measurement device.
A specific example of the application of the mode switching capability described above is a wristwatch which operates in a normal time indication mode (normal mode, normal driving mode) when the wristwatch is being carried by a user and also during a predetermined period of time after the end of the carrying state. If the predetermined period of time has elapsed after the end of the carrying state, the operating mode automatically switches to the power saving mode in which indication functions are partially stopped so as to save the stored electric power. This wristwatches returns to the normal time indication mode (normal mode) in which the current time is indicated by hands from the power saving mode in which the driving of the hands is stopped, in a manner as described below.
When the operating mode is returned from the power saving mode in which the movement of the hands (hour, minute, and second hands) is stopped to the normal time indication mode in which the current time is indicated by the hands, a single motor is generally rotated at a higher speed than a normal speed at which the hands are driven in the normal mode so that all hands are driven quickly to adjust the indication of time to the current time. In this technique, the hour, minute, and second hands are driven quickly by amounts by which the hands would have been driven during the period of time elapsed in the power saving mode if the operating mode were in the normal time indication mode.
In the conventional portable wristwatch described above, when all hands are quickly driven at the same time, a greater amount of electric power is consumed than required in the normal operating mode. In the case of a wristwatch using a battery to drive the hands, the increase in the power consumption can cause the power supply voltage to become unstable and thus can cause the adjusting of the indication of time to fail. Another problem is that because all hands are driven by the single motor, a large electric power is required to drive the motor itself, and a long time is required to adjust the indication of time.
A technique of solving the above problems is to drive the hands using a plurality of motors. However, if the plurality of motors are driven at the same time, the power consumption increases. Furthermore, the increase in the power consumption can cause the power supply voltage to become unstable and thus can cause the adjusting of the indication of time to fail. Furthermore, in the case where the hands are moved by small amounts in the operation of adjusting the indication of time, it is difficult for a user to visually recognize whether or not the indication of time has been correctly adjusted.
Therefore, it is an object of the present invention to overcome the aforementioned problems.
In view of the above, it is an object of the present invention to provide a time-measurement device which consumes less electric power in the operation of adjusting the indication of time which allows a user to easily recognize whether or not adjusting of indication of time has been correctly performed. It is another object of the present invention to provided a method of controlling such a time-measurement device.
In accordance with a first aspect of the present invention, there is provided a time-measurement device comprising: a power supply or power supply means for supplying electric power; a time indicator or time indicating means including a plurality of indication hand driving parts for driving corresponding indication hands using electric power supplied by the power supply means so as to indicate time by the plurality of indication hands; a controller or control means for switching the operating mode for each of the indication hand driving parts in accordance with a predetermined condition, between a power saving mode in which the corresponding indication hand is not driven and a normal indication mode in which the corresponding indication hand is continuously driven; an elapsed-time memory or storage means for storing the time elapsed in the power saving mode; and a time adjuster or adjusting means for adjusting indication of time by driving the indication hands using the indication hand driving parts in accordance with the time elapsed in the power saving mode when the operating mode is switched from the power saving mode to the normal indication mode; wherein the time adjusting means includes a time adjusting operation controller or control means for controlling the timing of driving the indication hand driving parts in the operation of adjusting the indication of time such that the plurality of indication hand driving parts are driven in a predetermined order and such that an overlap among adjusting operation periods of the plurality of indication hand driving parts is less than a predetermined value.
In accordance with a second aspect of the present invention, there is provided a time-measurement device wherein the time adjusting operation control means sets the adjusting operation periods for the plurality of indication hand driving parts such that there is no overlap among the operation periods.
In accordance with a third aspect of the present invention, there is provided a time-measurement device wherein the time adjusting means adjusts the indication of time such that, of the plurality of indication hand driving parts, an indication hand driving part having a lower normal driving speed is driven for adjustment before an indication hand driving part having a higher normal driving speed is driven for adjustment.
In accordance with a fourth aspect of the present invention, there is provided a time-measurement device wherein the time adjusting means adjusts the indication of time such that, of the plurality of indication hand driving parts, an indication hand driving part having a higher normal driving speed is driven for adjustment before an indication hand driving part having a lower normal driving speed is driven for adjustment.
In accordance with a fifth aspect of the present invention, there is provided a time-measurement device wherein the time adjusting means adjusts the indication of time such that the hour/minute hand driving means is driven preceding the second hand driving means, and the second hand driving means is driven after completion of the driving of the hour and minute hands.
In accordance with a sixth aspect of the present invention, there is provided a time-measurement device wherein when the time adjusting means adjusts the indication of time, the time adjusting means drives the plurality of hand driving parts by outputting driving pulses to the plurality of hand driving parts such that there is no overlapping in the timing of outputting the driving pulses.
In accordance with a seventh aspect of the present invention, there is provided a time-measurement device wherein when the time adjusting means adjusts the indication of time, a time adjusting driver or means drives a hour hand driver or driving means, a minute hand driver or driving means, and second hand driver or driving means in an exclusive fashion in the following order:
hour hand driving meansxe2x86x92minute hand driving meansxe2x86x92second hand driving means.
In accordance with a eighth aspect of the present invention, there is provided a time-measurement device comprising: power supply means for supplying electric power; time indicating means including indication hand driving means for driving an indication hand using electric power supplied by the power supply means so as to indicate time by the indication hand; control means for switching the operating mode in accordance with a predetermined condition, between a power saving mode in which the corresponding indication hand is not driven and a normal indication mode in which the corresponding indication hand is continuously driven; elapsed-time storage means for storing the time elapsed in the power saving mode; and time adjusting means for adjusting indication of time by driving the indication hands using the indication hand driving means in accordance with the time elapsed in the power saving mode when the operating mode is switched from the power saving mode to the normal indication mode; wherein the time adjusting means includes a time adjusting direction determination circuit or means for determining the direction in which the indication hand is driven to adjust the indication of time, in accordance with the time elapsed in the power saving mode.
In accordance with a ninth aspect of the present invention, there is provided a time-measurement device wherein the time adjusting direction determination means selects a direction, as the time adjusting direction, in which the indication hand is driven with less electric power than would be required to drive the indication hand in the opposite direction.
In accordance with a tenth aspect of the present invention, there is provided a time-measurement device wherein the time adjusting direction determination means selects a direction, as the time adjusting direction, in which the indication hand is driven in a shorter time than would be required to drive the indication hand in the opposite direction.
In accordance with a eleventh aspect of the present invention, there is provided a time-measurement device wherein when the angle R [xc2x0] required to rotate to adjust the indication of time is less than a predetermined value RT [0], the time adjusting means determines the time adjusting rotation angle RRET in accordance with the following equation:
RRET=R+360xc3x97n[xc2x0](where n is a natural number).
In accordance with a twelfth aspect of the present invention, there is provided a time-measurement device wherein when indication of time is adjusted, the time adjusting means maintains the second hand at the position where the second hand has been at rest during the power saving mode until the time indicated by the second hand at rest becomes coincident with the actual current time and starts to drive the second hand when the time indicated by the second hand at rest has become coincident with the actual current time.
In accordance with a thirteenth aspect of the present invention, there is provided a time-measurement device wherein when the angle R [xc2x0] required to rotate to adjust the indication of time is less than a predetermined value RT [20] and when an additional rotation angle is set to xcex1, the time adjusting means determines the time adjusting rotation angle RRET in accordance with the following equation:
RRET=R+xcex1[20],
and drives an associated hand in a first direction by the angle determined, and then drives the hand by the rotation angle xcex1 in a second direction opposite to the first direction.
In accordance with a fourteenth aspect of the present invention, there is provided a time-measurement device wherein when the angle between the hand position corresponding to the current time and the actual hand position is greater than a predetermined value, the time adjusting direction determination means selects the direction in which the hand is driven to adjust the hand position such that the indication hand is driven in a direction opposite to the direction in which the hand is driven in the normal mode.
In accordance with a fifteenth aspect of the present invention, there is provided a time-measurement device wherein the time-measurement device includes a plurality of indication hand drivers or driving means for driving different indication hands; and the time adjusting direction determination means determines the adjusting direction for each of the plurality of indication hand driving means.
In accordance with a sixteenth aspect of the present invention, there is provided a time-measurement device wherein the time adjusting means adjusts the indication of time such that, of the plurality of indication hand driving parts, an indication hand driving part having a lower normal driving speed is driven for adjustment before an indication hand driving part having a higher normal driving speed is driven for adjustment.
In accordance with a seventeenth aspect of the present invention, there is provided a time-measurement device wherein the indication hand driving means includes an hour/minute hand driver or driving means for driving a hour hand and a minute hand, and a second hand driver or driving means for driving a second hand; wherein the time adjusting direction determination means determines the direction in which a hand is driven to adjust the indication of time for each of the hour/minute hand driving means and the second hand driving means.
In accordance with a eighteenth aspect of the present invention, there is provided a time-measurement device wherein the indication hand driving means includes an hour hand driver or driving means for driving a hour hand, a minute hand driver or driving means for driving a minute hand, and a second hand driver or driving means for driving a second hand; and the time adjusting direction determination means determines the direction in which a hand is driven to adjust the indication of time for each of the hour hand driving means, the minute hand driving means, and the second hand driving means.
In accordance with a nineteenth aspect of the present invention, there is provided a time-measurement device wherein the power supply means includes an electric power store or storage means for storing electric energy.
In accordance with a twentieth aspect of the present invention, there is provided a time-measurement device wherein the power supply means includes an electric power generator or generation means for generating electric power by converting first energy to second energy in the form of electric energy, and an electric power store or storage means for storing the generated electric energy.
In accordance with a twenty-first aspect of the present invention, there is provided a time-measurement device wherein the first energy is energy selected from the group consisting of kinetic energy, light energy, thermal energy, pressure energy, and electromagnetic wave energy.
In accordance with a twenty-second aspect of the present invention, there is provided a time-measurement device wherein the power supply means is a primary battery.
In accordance with a twenty-third aspect of the present invention, there is provided a time-measurement device wherein the condition is the state in which electric power is generated by the electric power generation means or the state in which electric energy is stored in the power supply means.
In accordance with a twenty-fourth aspect of the present invention, there is provided a time-measurement device further comprising a carrying state detector or detection means for detecting whether or not the time-measurement device is being carried, wherein the condition is the state in which the time-measurement device is being carried.
In accordance with a twenty-fifth aspect of the present invention, there is provided a method of controlling a time-measurement device comprising: a power supply device for supplying electric power; a time indication device including a plurality of indication hand driving parts for driving corresponding indication hands using electric power supplied by the power supply device so as to indicate time by the plurality of indication hands; a controller for switching the operating mode for each of the indication hand driving parts in accordance with a predetermined condition, between a power saving mode in which the corresponding indication hand is not driven and a normal indication mode in which the corresponding indication hand is continuously driven; and an elapsed-time memory for storing the time elapsed in the power saving mode; the method comprising a time adjusting step for adjusting indication of time by driving the indication hands using the indication hand driving parts in accordance with the time elapsed in the power saving mode when the operating mode is switched from the power saving mode to the normal indication mode, wherein the time adjusting step includes a time adjusting operation control step for controlling the plurality of indication hand driving parts in the operation of adjusting the indication of time such that the plurality of indication hand driving parts are driven in a predetermined order and such that an overlap among adjusting operation periods of the plurality of indication hand driving parts is less than a predetermined value.
In accordance with a twenty-sixth aspect of the present invention, there is provided a method of controlling a time-measurement device comprising: a power supply device for supplying electric power; a time indication device including an indication hand driving device for driving an indication hand using electric power supplied by the power supply device so as to indicate time by the indication hand; a controller for switching the operating mode in accordance with a predetermined condition, between a power saving mode in which the corresponding indication hand is not driven and a normal indication mode in which the corresponding indication hand is continuously driven; and an elapsed-time memory for storing the time elapsed in the power saving mode; the method comprising a time adjusting step for adjusting indication of time by driving the indication hand using the indication hand driving device in accordance with the time elapsed in the power saving mode when the operating mode is switched from the power saving mode to the normal indication mode, wherein the time adjusting step includes an adjusting direction determination step for determining the direction in which the indication hand is driven to adjust the indication of time, in accordance with the time elapsed in the power saving mode.
Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings.